The present invention relates to medical and biotechnological devices and methods and, more particularly, to a membrane, a membrane-cannula combination and a connecting device for medical and biotechnological applications or uses, including uses in which sterility is involved. In some preferred embodiments, the invention is used in infusion means and methods, dialysis, perfusion or rinsing means and methods, and measuring means and methods.
In medicinal technology, in particular in human medicine, fluid guiding conduits—for example, catheters—have to be connected to each other, typically in sealed and sterile condition. Such a connection is particularly critical in the case of a body access device which is permanently implanted percutaneously or subcutaneously in a biological tissue, in particular in the human body. If a connection can only be established after the device has been implanted, or if it is to be possible to detach and re-establish the connection, then the demands on the sterile seal of a connecting point between the fluid guiding conduits increase.
Body access devices such as those to which the invention relates are known, for example, from EP 0 867 197, EP 0 867 196 and EP 0 867 198. In these devices, a sterile seal of a connection which can be repeatedly detached and established, between two fluid conduits within a percutaneously implanted port body, can be established by means of a membrane made of an elastic material. The membrane is arranged in the port body and comprises a self-closing passage. One of the fluid conduits is an implanted catheter guided into the port body. The other fluid conduit to be connected is formed by a rigid, thin cannula which can be inserted into the passage. The membrane surrounds an outer surface of the cannula inserted into the passage, forming a seal all around. The membrane creates a sealed connection in the port body between the implanted catheter and the cannula guided into the port body from outside the body.